In a windowless basement classroom, a dozen teens sat in groups of two and three around a large table, quietly consulting one another over laptops. They wore scarlet polo shirts, black pants, shoes, and might have been mistaken for high-tech workers if a visitor didn’t know they were part of the first class to graduate from the Pioneer Charter School of Science in Everett.

On Tuesday, the
charter school held its first commencement ceremony, with 34 seniors receiving high school diplomas. At least 30 of the graduates have been accepted to four-year colleges, and, to date, the group has been offered $3.2 million in scholarships. Students and educators say the academic achievement comes down to two words: hard work.

“We have high expectations from the teachers and the students,” said Barish Icin, the school’s executive director.

Like many of the schools in urban districts north of Boston, the students face numerous challenges outside of the classroom. About half of the 315 students, who come from Everett, Chelsea, and Revere, live below the poverty level, speak a different language at home, and come from single-parent families.

To boost academic achievement, the school implemented a rigorous curriculum. It has an extended learning calendar, with students attending school for 200 days a year — some 20 days more than the public school model of 180 days — and classes beginning in late August and running through late June. In addition, students are encouraged to spend at least an extra hour a day at tutoring sessions or taking part in sports or clubs, and about a quarter of the school’s pupils come for tutoring on Saturdays.

Students must pass five math and five science classes in order to graduate, and also must complete 40 hours of community service.

Summer school is offered. Students are encouraged to contact their teachers with questions by e-mail or cellphone after hours. Besides the school uniform of a polo shirt, pants, a belt, and shoes, all electronics — such as phones, iPods, and laptops — are forbidden during school hours and are collected by teachers each morning before the first class begins.

With the extra classroom hours and a heavy emphasis on math and science, Pioneer students have outpaced MCAS state averages and local district scores. According to the Massachusetts Department of Elementary and Secondary Education, the school placed in the top 25 percent statewide based on percentage of students who scored proficient or advanced in English and math in grades 7, 8, and 10.

Educators and students say the extra learning time has helped boost academic achievement. As part of the curriculum, students in grades 7 through 10 take two hours of math each day, and Grade 9 students take a double load of science each day.

Icin said the focus on math and science will help the students find work after they leave Everett. “We expect all of our students to go to college and we convey that message to them from Grade 7,” said Icin. Each grade is broken into three groups, named Yale, MIT, and Harvard. Classes range from 20 to fewer than 10. During the year, educators from Harvard and other Boston-area colleges come to the school to lecture. Field trips take the students from Everett to area colleges.

Last week, before the graduation ceremony, seniors began saying goodbye to classmates and teachers. Most said they were grateful that the school had instituted a rigorous curriculum and structure.

“I don’t think a public school would have been as challenging,” said Momoh Osilama, 17, who has accepted a scholarship to attend Columbia University in New York. Osilama was born in Nigeria
and came to Revere as an infant with his family. Prior to enrolling at Pioneer, he attended a private school in Revere.

“When there’s a lot of order in the early stages of your life, there’s a more guided path for your future as an adult,” said Osilama, who hopes to become a doctor.

Deandra Cora entered Pioneer four years ago and thought that after graduating high school, she would become a hair stylist. Since enrolling, the Chelsea teen became captain of the girls’ basketball team, earned good grades, and recently accepted a scholarship offer to attend Nichols College in Dudley.

Cora also thinks the school’s structure helped shape her future. “They’re very disciplined here, which helps kids. I feel like it put me on the right path. Without structure, kids can end up anywhere,” she said.

Ariana Gonzalez of Everett also hopes to become a doctor and has accepted a scholarship to attend Boston College. At 18, she has already taken numerous AP courses at the school, spending up to six hours a night on homework. She credits the close-knit classes for pushing her to succeed.

“The atmosphere in the classroom is very competitive and you always want to be the top student,” she said.

Steven A. Rosenberg can be reached at srosenberg@globe.com. Follow him on Twitter @WriteRosenberg.